This invention is concerned with enhancing the performance of a propeller on a spinner, and is more particularly concerned with a device and method employing a turbine for providing a contribution to propulsive thrust of a propeller.
It has previously been proposed to improve the propulsive thrust of an aircraft propeller, e.g., by adding additional propeller blades, by modifying a propeller spinner to provide ridges or grooves acting as air screws, by providing a hollow propeller hub with vanes, or by providing blades or vanes on a propeller hub that are intended to sling air at right angles to the vehicle velocity vector, supposedly to increase the mass of air for the propeller to work on. For various reasons, including, e.g., increased turbulence and drag, and increased complexity and cost, the prior art proposals have been deficient. The present invention avoids the deficiencies of the prior art and enhances the performance of a propeller on a spinner in a manner that is simple and cost effective.
In broad terms, the invention involves the addition of a turbine to a propeller spinner, such as a conventional aircraft propeller spinner. In a preferred form, the turbine is provided as a group of turbine modules that are mounted on the spinner between root portions of the propeller blades. The modules are made in matched sets of equal weight to preserve the propeller dynamic balance, and do not interfere with normal propeller operation.